Wireless sensor assembly for circumferential monitoring of gas stream properties

Abstract

A wireless sensor assembly for circumferential monitoring of gas stream properties comprises a drive system attachable to a hot gas path housing. A rake is movably coupled to the drive system for unrestricted circumferential movement. At least one RF sensor is disposed on the rake for generating a signal responsive to the gas stream properties. Circuitry is provided for remotely powering the at least one RF sensor and for remotely detecting the signal.

What is claimed is:  
     
       1. A wireless sensor assembly for circumferential monitoring of gas stream properties comprising: 
       a drive system attachable to a hot gas path housing;  
       a rake movably coupled to said drive system for unrestricted circumferential movement;  
       at least one RF sensor disposed on said rake for generating a signal responsive to said gas stream properties; and  
       circuitry for remotely powering said at least one RF sensor and for remotely detecting said signal.  
     
     
       2. A wireless sensor assembly in accordance with  claim 1 , wherein said wireless sensor assembly is capable of operating at temperatures of greater than about 200° C. 
     
     
       3. A wireless sensor assembly in accordance with  claim 2 , wherein said circular drive path mechanism is at least one of a chain or a cable. 
     
     
       4. A wireless sensor assembly in accordance with  claim 3 , wherein said chain or cable is capable of operating at 1400° F. (760_° C.) or greater. 
     
     
       5. A wireless sensor assembly in accordance with  claim 3 , wherein said chain is made of stainless steel. 
     
     
       6. A wireless sensor assembly in accordance with  claim 1 , wherein said drive system is a circular drive path mechanism. 
     
     
       7. A wireless sensor assembly in accordance with  claim 6 , wherein said circular drive path mechanism is a circumferential channel. 
     
     
       8. A wireless sensor assembly in accordance with  claim 1 , further comprising a prime mover disposed outside said hot gas path and coupled to said drive system for circumferential movement thereof. 
     
     
       9. A wireless sensor assembly in accordance with  claim 1 , wherein said drive system moves in the range between about 10_°/minute to about 360_°/minute. 
     
     
       10. A wireless sensor assembly in accordance with  claim 1 , wherein said drive system moves in the range between about 48_°/minute to about 90_°/minute. 
     
     
       11. A wireless sensor assembly in accordance with  claim 1 , further including a position detection control mechanism. 
     
     
       12. A wireless sensor assembly in accordance with  claim 1 , wherein said position detection control mechanism is a timer. 
     
     
       13. A wireless sensor assembly in accordance with  claim 1 , wherein said rake is a rod. 
     
     
       14. A wireless sensor assembly in accordance with  claim 1 , wherein said rake is a bifurcated rod. 
     
     
       15. A wireless sensor assembly in accordance with  claim 1 , wherein said rake is an angled rod. 
     
     
       16. A wireless sensor assembly in accordance with  claim 1 , wherein said rake is made of a material selected from the group consisting of Hastelloy, a nickel-based alloy and a cobalt-based alloy. 
     
     
       17. A wireless sensor assembly in accordance with  claim 1 , wherein said drive system further comprises a carriage mount for coupling said rake to said drive system. 
     
     
       18. A wireless sensor assembly in accordance with  claim 17 , wherein said carriage mount is capable of operating at temperatures greater than 1400° F. 
     
     
       19. A wireless sensor assembly in accordance with  claim 17 , wherein said carriage mount positions said rake substantially normal to said hot gas path housing. 
     
     
       20. A wireless sensor assembly in accordance with  claim 1 , wherein said RF sensor comprises an LC circuit including an induction coil and a capacitor having a dielectric material, which dielectric material has a dielectric constant that is a function of temperature. 
     
     
       21. A wireless sensor assembly in accordance with  claim 20 , wherein said dielectric is capable of sensing temperatures of at least 900° F. (482_°C.). 
     
     
       22. A wireless sensor assembly in accordance with  claim 21 , wherein said ceramic base is selected from the group consisting of alumina and zirconia. 
     
     
       23. A wireless sensor assembly in accordance with  claim 1 , wherein said RF sensor is responsive to a frequency of at least 1 MHz. 
     
     
       24. A wireless sensor assembly in accordance with  claim 1 , wherein said RF sensor is responsive to a frequency in the range between about 200 MHz to about 600 MHz. 
     
     
       25. A wireless sensor in accordance with  claim 1 , wherein said RF sensor is sensitive to a property selected from the group consisting of temperature, NOx concentration, salt concentration, oxygen concentration, carbon monoxide concentration, carbon dioxide concentration and particulate concentration. 
     
     
       26. A wireless sensor assembly in accordance with  claim 1 , wherein said RF sensor has a ceramic base. 
     
     
       27. A wireless sensor assembly in accordance with  claim 1 , wherein said circuitry is a pulsed circuit. 
     
     
       28. A wireless sensor assembly in accordance with  claim 1 , wherein said circuitry includes a power source, a microprocessor and an RF detector. 
     
     
       29. A wireless sensor assembly in accordance with  claim 28 , wherein said circuitry further includes a data acquisition device. 
     
     
       30. A wireless sensor assembly in accordance with  claim 29 , wherein said circuitry includes at least one antenna disposed upon said housing. 
     
     
       31. A wireless sensor assembly in accordance with  claim 30 , wherein said at least one antenna is two antennas spaced apart by 180°. 
     
     
       32. A wireless sensor assembly in accordance with  claim 31 , wherein said at least one antenna generates a signal to power said RF sensor. 
     
     
       33. A wireless sensor assembly in accordance with  claim 31 , wherein said antenna generates a signal having a bandwidth to cover the range frequencies for each respective RF sensor. 
     
     
       34. A wireless sensor assembly in accordance with  claim 31 , wherein said antenna generates a signal having a bandwidth with a specific frequency related to a specific RF sensor. 
     
     
       35. A wireless sensor assembly in accordance with  claim 31 , wherein said antenna sends pulses to said at least one RF sensor. 
     
     
       36. A wireless sensor assembly in accordance with  claim 31 , wherein said RF detector can discriminate between frequencies to determine which RF sensor is detected. 
     
     
       37. A wireless sensor for circumferential monitoring of gas stream properties within a hot gas path housing, said sensor comprising: 
       an RF sensor for generating a signal responsive to said gas stream temperature said RF sensor including an induction coil and a capacitor, said capacitor having a dielectric material, which dielectric material has a dielectric constant that is proportional to temperature;  
       an antenna for generating signals to power said RF sensor;  
       an RF detector for detecting the signal generated from the RF sensor; and  
       a microprocessor coupled to said RF detector to correlate the detected signal with the temperature of said gas stream.  
     
     
       38. A method of monitoring gas stream properties within a hot gas path comprising the steps of: 
       positioning an RF sensor sensitive to a respective gas stream property within said hot gas path for generating a signal responsive to said property;  
       rotating said RF sensor about said hot gas path housing;  
       remotely powering said RF sensor;  
       remotely monitoring said generated signals; and  
       detecting said generating signals.